1. Field of the Invention
The present invention relates to an electronic control system for a vehicle and a control method thereof, and more particularly, to an electronic control system for a vehicle and a control method thereof, wherein communication is made between a main controller and at least one local controller to control a brake apparatus and a suspension apparatus in consideration of information of the controllers, thereby further improving and activating unique features of the respective controllers as well as simplifying the system.
2. Description of the Related Art
An electronic control system for a vehicle is currently an important issue of development companies, and many studies thereon have been conducted.
As shown in FIG. 1, such an electronic control system comprises an electronic stability program (ESP) controller 10 for a brake apparatus, a continuous damping control (CDC) controller 20 for a suspension apparatus, a tire pressure monitoring system (TPMS) controller 30 for a low tire pressure alarm system, and an interface unit 40 for performing communication among the respective controllers 10, 20 and 30.
Here, the ESP controller 10 receives information from a wheel speed sensor 1, a steering angle sensor 2, a yaw-rate sensor 3, a lateral acceleration sensor 4 and a brake pressure sensor 5, and controls a brake control unit 6 and an engine control unit 7.
The CDC controller 20 for a suspension apparatus receives information from a vehicle body acceleration sensor 21, a wheel acceleration sensor 22, a steering angle or yaw-rate sensor 23 and a lateral acceleration sensor 24, and controls a damper control unit 25.
The TPMS controller 30 for a low tire pressure alarm system transmits tire pressure information of a tire pressure sensor 31 to a controller having a receiver in a radio frequency (RF) transmission manner and displays the tire pressure information on a display unit 32. Accordingly, a driver can confirm the tire pressure information.
In this manner, the electronic control system merely exchanges the information, which is received from the sensors connected to the controllers 10, 20 and 30, with the controllers. Thus, even though the controllers 10, 20 and 30 are installed, they do not affect the performances of the others. That is, the electronic control system individually operates unique characteristics of each of the controllers 10, 20 and 30 using information received from a corresponding sensor.
Accordingly, since information required by each controller is received from a sensor connected to each controller and is then processed, sharable sensors (e.g., the steering angle sensor, the lateral acceleration sensor, and the wheel speed sensor) are redundantly used, leading to an increase in the unit cost of the system.
In addition, since sensors required by respective controllers are redundantly installed and controllers (e.g., the CDC controller) are installed individually so that the controllers can be operated independently, it is inefficient in that the inner configuration of the system is complicated and signal processing thereof is duplicated.
Further, in most of TPMSs, an RF receiver is mounted on the controller to receive information from a pressure sensor of each wheel. However, since frequency allocation bandwidth of each country is different from those of other countries, a receiving rate is lowered if a weak frequency is allocated.